Blade sharpener



FIG. 1 is a top perspective view showing my new design;

FIG. 2 is a left side view in elevation thereof;

FIG. 3 is a right side view in elevation thereof;

FIG. 4 is a top view in plan thereof;

FIG. 5 is a bottom view in plan thereof;

FIG. 6 is front view in elevation thereof; and,

FIG. 7 is a rear view in elevation thereof. 

The ornamental design for a blade sharpener, as shown and described. 